#202

This is something anyone can do. You don't need special skills....

[@cwebs1000]

Now we know why you keep your hair so short Peter. It's so you don't grab handfuls of hair and pull it out when working behind people that make such a mess of the radios.

[@hectorpascal]

How can ANYBODY treat a radio that STILL sells for ~$1000 like that! It almost physically hurts me to see it! I know Peter loves a challenge, but surely this one was always well beyond the call of duty!

[@gd9704]

A man's got to know his limitations. The owner of this radio didn't know his.

[@TRXLab]

you are 100% right

[@mauricelackey5324]

Got to have a good magnifier, good TEMP controlled soldering iron with right size tip as a minimum.

[@markkut9419]

So many spoil good radios when can't do nothing enough good. But here is always them who think can do everything.

[@VintageTechFan]

I'm an electronics engineer, quite experienced with soldering (not that much of an expert in surface mount) and I got kinda nervous opening up my european IC-7000 (to open it up for the back then newly allowed 60m band) and took a lot of care and was relieved not to have fried anything.

[@BruceNitroxpro]

This is a painful video to watch on so many levels. No other comment necessary.

[@TRXLab]

yeah you are right

[@GeorgeWMays]

I have no knowledge of this radio. But is that an RS232 port on the back of the radio? Hook up a breakout box and see if the UART initializes (built into the processor?). If it does, is there anything on the TD or RD leads? I say this because as a programmer from this era it was very common to squirt out status messages during initialization of the system and to send error codes (in ASCII) if something goes wrong. Just a crazy random thought....

[@TRXLab]

Good point George...Thanks for comment

[@thefreese1]

I see America isnt the only country with people who take the golden screwdriver to perfectly good radios... most techs wouldn't even touch a radio that was jacked up this way. Kudos do you Peter Peter you went well Way Beyond the Call of Duty on this one. We all can tell that you know how to accept a big challenge . The best tech on KZbin in my book

[@neilawaud2061]

Excellent video, very informative. Just a suggestion, press the fast and lock buttons together at the same time and turn the radio on this will reset the micro, it’s just a suggestion but it might be that at boot up, some of the initialize code is corrupted, leading to an ‘unknown-status’. There is probably enough code available to ‘force-shutdown’ rather than enter a possible ‘burn-out’ status. One final suggestion, this is from my early PC service days, when a ‘486DX2-66’ was a fast processor. My original IBM PC has directional detection on the CPU Cooling-Fan, if the fan was seized, and not running, the system would lock-down rather than overheating, if the Fans on the FT-847 are not running, could that force the fault you are seeing? Great video again, Bye-4-Now - Neil G1OVH - UK-QTHR.

[@stopnwonow5044]

24:43 Sad... What a stupid way to ruin a beauty high-class radio !.. Seriously, I can't believe it..

[@StreuB1]

Oh man.....1hr 20min video from Petr and at 6:00, we already see this is going to be another case of "The man with the Golden Screwdriver." This is going to be good, I already know it!

[@paulmichaelson7203]

This was not a golden screwdriver, this was a golden sledgehammer. I have an FT-847 and it still works fine. It's a great radio and it saddens me to see one mangled like that. This is proof that some people shouldn't work on electronics.

[@StreuB1]

@@paulmichaelson7203 You aren't kidding. I think there are some people who shouldn't even be allowed to own nice things, let alone electronics more complex than a hairdryer.

[@paulmichaelson7203]

@@StreuB1 Yup, I bought my 847 new in 1997, I've put filters in it, done other mods like the MARS mod, never replaced the power switch and the rig still works like new. It is one of only a couple of rigs that will do cross band full duplex and makes SAT operation easy and fun. I love that little rig and I'll never sell it. It's a shame to see one go so needlessly. I bet 90+ percent of 847s are still operating. Nothing can live forever especially in the wrong hands. 73 de k8idx. 73 to you too Peter, I love your videos.

[@danielhowiesr.2593]

Peter, you don't give up easily! That radio was terribly abused. Thanks for the video!

[@mikesradiorepair]

Welcome to my world. The world of butchered and hacked up radios. I swear there are days I spend half the day just shaking my head in disbelief. The sad thing with this radio is before someone started butchering the radio it was probably a easy repair. People need to learn their limits. Good attempt on the repair.

[@paul-c7541]

Hi Mike I've seen your video's the patience of a saint, it's seems like let's kill a cb then send it to Mike

[@TRXLab]

LOL yeah I know OUR world very well Mike and the issue is it take to much time for a no fix. I guess I have to update my no fix policy...

[@ethanpoole3443]

TRX Bench FWIW, I feel it is perfectly fair to charge for time invested into a no-fix, but especially in the case of a butchered PCB where you are likely dealing with multiple atypical faults simultaneously as they can take enormous time to troubleshoot and repair.

[@AndrejaKostic]

Wow! That repair work on the vias was really amazing!

[@paul-c7541]

Hello Peter,I can only tell you about an experience I had with a MEOS TV I have it did the same as your radio, I checked the capacitors, and the diodes in the power supply, all was well, board looked clean nothing showed up no smells, so I put freeze spray on section of the board at a time and switched on, eventually I went to one section powered on and immediately one component thawed out, it was one of those smd caps, so I got the part number off the schematic and I swapped it out, bingo the TV fired up, wife was happy I was relieved , so as the board your working on has been messed about with, could this method help you out. 73 Paul M0BSW

[@TRXLab]

Thanks Paul very good approach and a valuable step forward! 73

[@izzzzzz6]

i just wrote this in a reply to an earlier comment, glad you came up with this one.

[@USA-LEO]

Great video!!! I have the same radio that I bought in 1999 for $1500, I've never used it, it's brand new, still packed in the box! Is there anything I should do with the new one that's been packed away for 20 years before I start it for the first time? Thank you in advance! Currently living in 🇬🇧 KE6MFK Merry Christmas 🎄

[@jeffdyer2109]

If you have access to an infra red camera you may be able to see the offending component at power on. Jeff.

[@terrym3543]

Have you tried doing a factory reset on the radio? when I have done this kind of mod on other types of radio sometimes the CPU gets confused.

[@zman4150]

Call or email Yaesu UK - they may be able to provide that chip for you. They helped me find an obsolete part for another rig.

[@tlrptg]

it's not the processor. keep digging. (reheat the soldering of the processor, with hot air, without removing it from the board. The solder Yaesu used tended to crystallize and make intermittent or no contacts after 20 years of use.)

[@TRXLab]

Thanks Pop that is a good hint. I know this issue when the solder melts it feels like chewing gum. I always test the IC pin by pin with a sharp hook and normally you will find a loose connection by this approach. In this case all the pins were in good condition.

[@1flatlander380]

Visible proof you cannot use an acetylene torch for SMD soldering. LOL

[@jonka1]

I was wondering if a chainsaw was used to remove the original parts as well.

[@montygore1200]

Hi Peter. That was an amazing video. I have many years experience and I would not have gone as far as you did. Your videos and so informative that I have watched most all of them. you are one of the best I have ever learned from. I am retired now but i still dabble a little from now and then. thank you for your effort.

[@TRXLab]

Thank you!

[@Zein-xx1gy]

Thanks a million Peter for all your help and patience with the messed up radio. Great video with learning aspects

[@BrendaEM]

I feel that you were very kind to the person who tried to "fix" the radio before--as if they were your in-laws. It's a self-esteem radio, to make you feel good about the quality of your work. The resistor was added for added inductance : )

[@wakkowarner7391]

It's like a tornado picked up a bunch of chisel tipped soldering irons and then went over the board. Horrendous!

[@lyntonprescott3412]

You have so much patience. Great video. Show the owner a red card in the future! 73’s Lynton

[@TRXLab]

Thanks Lynton 73

[@mickyjb2003]

Amazing how people will try to Hack up something with know real knowledge of what they are doing.

[@ethanpoole3443]

Indeed, there is a world of difference between possessing some printed instructions on how to perform a mod versus actually executing those instructions...assuming that the initial instructions were at least correct. SMD parts in modern radios can be quite small and closely spaced so you have to be very cognizant of where your heat is going and how it may affect nearby components. Just in the opening minutes of the video it looks like somebody really went at the board...I could do finer soldering with a torch than was done to this board. Whatever they did, they certainly got a great deal of heat into that board to have removed traces and melted and damaged components over such a large area.

[@markwarren7116]

@@ethanpoole3443...All Techs know a good rule of thumb is "NEVER" use a chisel tip for these SMD's and never use a soldering iron more then 20 watts. And never solder or unsolder more then 3 seconds....You got alot of wannabe techs out there these days!

[@tim46767]

The radio is on for a few time. Solution: replace the on switch with a 555 timers ;-)

[@simonemeggiato4650]

Hahaha!

[@waynethompson8416]

I really appreciated and enjoyed this video. It brought back horror memories of my Kenwood TH-F6A that went into meltdown because the "ON/OFF" "switch" was not an actual switch but a "soft switch" which would not allow me to turn it off as it went into meltdown. The protective covers on the right side (mike, speaker, etc.) were missing and some jerk nearly hit me causing the contents of a coffee cup to be spilled into the rig via the jacks on the right side. The battery would not come off unless I removed the belt clip, and since I was driving down the interstate I had no screwdriver to do so. I do wish I could get it working again, but I fear that like the one you worked on in this video, it is simply not cost effective. There were a couple of times that I thought I saw a problem that you may have missed. One such item is at 38:24 in the video. In the upper right part of the screen is a bit of debris that it appears that you didn't see since it didn't show you removing it. There was also a bit of debris above the trace of the bottom left resistor between the trace and the ground plane. You may have taken care of both of those, but I didn't see it, so I couldn't know for sure. Keep up the excellent work!

[@mm3nrx]

Jeezo! someone has rap*d that lovely radio :(

[@octavmandru9219]

I am more amazed how people do something really bad, then try to undo and destroy more, and than just downplay their works. "I cannot understand why it doesn't work anymore" I hope you made him pay a pretty penny for this

[@iw0hex]

Great video Peter, much patience and great skill. Thanks for sharing your videos. 73s Pasquale IW0HEX

[@tomg1004]

Great video as always! Thumbs up! I had a peek at the schematics and had one far-fetched thought: What if the undefined state of the broken backup battey switch (S1001) confuses the CPU? Since that switch looked molten to death by a soldering iron and it is close to where the "mod" was done, I thought it might be a possibility even if it might not be a likely explanation. The backup battery switch leads straight to one pin on the CPU. In off state that pin is grounded via 10k and in on state it has 3V from the Lithium cell.

[@TRXLab]

Yes you are right. For testing I had the switch hard wired for exactly this purposes. Good thought thanks....

[@stevejones8665]

@@TRXLab The Backup Memory Switch is nothing to do with this problem the Radio will work without the Switch or indeed any Backup Battery, all that happens is it will not hold a y memories when powered off If you keep power connected then the Memories and the Radio will still work all ok...I have a Yaesu FT920 with very similar design with the Backup Switch and Battery...Best of Luck fixing it....Looks like a Butcher has tried to do Soldering with a large Hot Poker from the Coal Fire hi hi....Such a Shame.

[@MrBanzoid]

Was this mod done with a blowtorch? Another great vid, 73 de Malc 2E0EZP.

[@stevejones8665]

Yes most likely a Plumber by Trade (No disrespect to Plumbers) or a Red Hot Poker.

[@ComputerLearning0]

I bought an FT-847 the first year they came out and I remember there was a recall for the power switch and I really didn't want to have to ship my 847 to Yaesu just to replace a silly power switch. My radio wasn't exhibiting any kind of problem but after talking with Yaesu they sent me the replacement switch, which I happily replaced on my own.

[@MrPerrey]

Hi Peter - what a messy service You picked up!! May be CPU is reading a corrupted setup data on booting and shuts down. To reset CPU and config on radio startup make sure the radio is OFF, then press and hold the and button's and turn the radio ON. (!!Warn the customer that all the contents of the memory channels will be reset and lost. :-!!) - Did You replaced the messed up battery switch? Did You checked the supply close to the processor during power on? (Nominal value and max ripple)

[@TRXLab]

Thanks Wolfram I have tested it but no change...The battery switch is hard wired...The caps on the processor power line are new

[@ve3krp]

I own two FT-847's and to see this makes me very sad and a bit angry... I had a similar problem on one of mine but it was the power switch itself. If I held down the switch it stayed on. Eventually temporarily did the mod for the switch and then replaced it... Great video and keep up the work !

[@TRXLab]

Yeah the power switch is a known issue on this radio...

[@orangetest999]

I've been looking for any FT 847 boards...but 800 to 1200 USD for a 20+ year old radio...got to love the US ham market . :)

[@johncundiss9098]

Feel sorry for what was a good radio. I know this. I feel Mr. consumer should still be paying you for the time spent trying to fix. He is the one that took the blowtorch and rusty screwdriver to it.

[@crazy4volvo]

I know it's a 5 years old case, but anyway... I got similar fault in very fast, 2x9pin needle printer with huge power supply unit. The PS unit was switching off after about two seconds from Power On. All voltages were OK (I had to measure them with oscilloscope), no symptoms of shortage in the mainboard, motor drivers etc. The PS was receiving an "emergency power shutdown" signal from CPU. The problem was caused by one of the resistors in voltage divider measuring one of the PS output lines. It changed the value from 20k to 40k, so the measured voltage seen by CPU was 3V instead of 1.5V. So it looked like an overvoltage and CPU immediately halted the PSU. It took me 3 days to find this resistor as at first glance 3V looked quite a good value for a 5V Z80 based CPU, until I made proper calculation ;).

[@zaperfan]

The conclusion is send your radio to a professional to make the modification. Great video Peter thanks for posting

[@TRXLab]

you are right.Thanks for watching 73

[@SophiesKitties]

I want to use SMD 0201 size, 0 ohm jumpers for the JP1 001 - JP1 006. I was wondering if this would be the correct size. BTW, I'll make sure I'm wearing a ESD Wrist Band. these jumpers are connected directly to the CPU. Very nice Videos...

[@JamesGMunn]

Good of you to show us even when it is not fixed. I would recommend focusing on the destroyed vias etc. in the mode area 1, 2, 3 and 4 at 7:41. Most of the time, it is the last thing that "changed" that is the culprit. The processor is booting up and even running long enough to switch modes and receive. So the processor is probably fine. It has to be some input to the processor, analog or digital input, if it is the processor shutting it down. I am sure you checked that any DC to DC power supplies are not causing the shutdown. Are there any protection circuits/blocks? Did they mess with the bias settings?

[@TRXLab]

Thanks James, yeah destroyed vias are a problem but can't find any additionally..DC/DC has been checked out and are found good...

[@btouw8558]

how it is possible to injure a pcb like that is bejond me, and unnessesary,

[@TRXLab]

yeah good question....

[@bsb0011]

I would try using an logic analyzer configured to trigger when the reset goes low. I would also set the LA so that there is a healthy pre-buffer before trigger, so you can connect many inputs of the LA to various test points on and around the processor, and then be able to go back and see what happened right before the processor reset. I would also make sure to monitor any interrupt type of pins in relation to the reset line. Could be an additional fault that is generating an interrupt signal that the firmware is decoding to be a power off condition. Last resort would be the "shotgun" approach and simply test all pins in relation to reset, again seeing if anything is happening right before the reset goes low. My last ditch effort would be to freeze the board real good and see if you have any caps or other components that have failed short. Ceramic caps of that era are known to fail short, so you might see that if any device instantly heats up. Should all that fail, I would suggest the owner buy a donor board like you suggested (that and revoke his soldering iron license till he takes a certified soldering class!). (edited to remove suggestion of tying the battery switch one way or the other, as i failed to notice your comment on the subject)

[@TRXLab]

Thanks for comment

[@trcostan]

I assume he doesn’t do this work for free! At some point it just doesn’t make sense for him to keep billing hours!

[@TM-hx7mm]

My comment has more than likely already been covered, And this video is fairly old now, But all the time watching this i was thinking "I'm sure the backup battery has to be connected for it to power on" And when you first opened it there was a backup battery someone bodged in, but the backup switch was broken so the battery wasn't actually in circuit, Did you ever try a new battery and replace switch, Or solder the two tabs of the switch together so its on ?

[@pu2xbt74]

I want to buy a RAdio VHF / UHF to contest DX FM / SSB and I am thinking of buying the YAESU FY 847, please can you help me with suggestion ??? 73 PY2RZ

[@wb6wsn]

Since even the panel lights shut off, I would assume that the power supply is receiving a disable command from somewhere. What supplies that command and can you monitor that control input to the power supply? Can you disconnect that line and maybe force the power supply to be enabled (or not disabled)? How about finding an FT-847 support group on Yahoo or Facebook where you can discuss this problem with hard-core enthusiasts? These groups often have community files with factory service manuals and a wealth of undocumented knowledge. The odds are high that you are not the first person to experience this auto shutdown condition.

[@RadioWhisperer]

Finding the source of the shutdown was my thought as well. It may just lead back to the processor, but there has to be some circuit triggered by the processor to cut off power. See if that circuit is rogue. Or being commanded. Also, if you can find a working radio, compare the startup serial protocol of the working radio to the dead one. If they are different, you might have another clue. All the better if you can get Yaesu to send you the protocol specs. I imagine the header includes a target device address. And the reply may have error codes that give a clue to the root cause. If the serial is I2C or SPI your scope may decode the hex values being sent.

[@TRXLab]

I have tested the shout down circuit and it is working just as it should. Anyway good thought thanks

[@wb6wsn]

@@TRXLab Yes, fine, but can you over-ride the shut-down system? Either disconnect it or strap it enabled, and see if the rest of the receiver might then work.

[@TRXLab]

yes I have hard wired from an external voltage supply to overrule the circuit but no change...

[@wb6wsn]

@@TRXLab So if you hard-strap the shut-down command signal to the power supply, the power supply still shuts down? That seems to tell us to look at why the PS is shutting down without a shut-down command. I have encountered military power supplies that go through some odd output excursions right after start-up, and internal watchdog circuits shut them down. Put an oscilloscope on the PS outputs and see how cleanly the power comes on. Also try running just the PS, with no connection to the radio. Does it still shut down? Lastly, look at the signal path from the shut-down input of the PS to the device in the PS that actually does the switching action. Perhaps we are in that strange land where the error protection circuit is causing the error.

[@philkennedy342]

Wow that’s one wrecked radio unbelievable… Unfortunately there’s to many spanner jockeys clearly no idea of electronic repairs…. That’s in a real mess!!!

[@whitefordpipeshandmadebymi7238]

Wow I don’t want to hurt anyone’s feelings but man they should not do soldering work anyway 73 de ve3hip in welland Ontario Canada 🇨🇦

[@montygore]

Great video. I learned some troubleshooting from you and I have been repairing for many years. You are one of the VERY best. Thank you

[@TRXLab]

Thanks for your feed back, very much appreciated

[@raymitchell2965]

The golden screw driver strikes again soldering with a hot nail

[@F_Tim1961]

I think you meant against ... TEF

[@dh8dl]

Ich würde als erstes nochmal den Ein/Aus-Schalter überprüfen ob der auch wirklich noch im gedrückten Zustand den Kontakt schließt und nicht nur während des drückens.. Wie du schon sagtest ist der bei dem Gerät anfällig, deswegen wurde die zweite Schalterhälfte ja schon mit Kabeln dazu geschaltet. Als zweites dann den defekten Backup Schalter neben dem Prozessor ersetzen, dadurch das der obere Teil fehlt wird ja jetzt gar kein Kontakt geschlossen, dadurch könnte der Prozessor vielleicht blockiert sein. Und natürlich die Batterie wieder anlöten nicht vergessen.

[@TRXLab]

Der Ein Aus Schalter ist nicht das Problem da ich den auf dem CNTL Board gebrückt habe...Der Back Up Schalter ist mit einem Kabel verlötet..

[@prestonshute7243]

Good try, but what someone did was a total train wreck to that radio. 73 wd4dda

[@TRXLab]

Yeah that it is total train wreck. Thanks for watching 73

[@markwarren7116]

Who ever tried to do the mod really messed up a very nice radio. If they were trying to do the MARS & CAP and 60 Meter mod, then why did they do all that other garbage?...All they had to do was to do take out a zero Ohm resistor and bridge a pad or 2 next to the battery. All of that other garbage was unnecessary. I modified a few of these in my time. What in Gods name kind of a mod was that idiot trying to do!

[@ryantoomey611]

Now on Craigslist: Ham radio for sale. Does not work, do not know whats wrong with it but was tuned for maximum smoke the last time it worked. No lowballers! I know what I have. It is worth lots of money when working and can be easily fixed with the proper tools.

[@ethicalfarmer7424]

LOL MARS mod using a 1940s plumbers soldering iron.

[@TRXLab]

LOL yeah right

[@the1spyderryder]

Why would you not check the power switch and power supply first? Find out why the radio is not staying powered whether it is a supply problem. It sounds like the latch on the switch is releasing or a relay is dropping out when it shuts down. Solder one side of the resistor to one of the pads then extend the other pad to the resistor with a wire. Again fix the flipping reason that. The power goes off first¡ Is that a multilayer PCB!

[@stuarthall3874]

As far as I'm concerned, the owner can do whatever he wants to his own radio. It's no skin off my nose if he bricks it. I am more distressed by people who decide it is helpful to heap criticism on top. That is contrary to the mission of amateur radio in that such criticism can discourage people from experimenting. It is amateur radio, not professional radio and I try to always be welcoming and encouraging to anyone who wants to participate. It is not a place to play "King of the Mountain".

[@dirkr7891]

This Radio is one of the worsest Yaesu ever made. Selectivitity on ist very Bad and it have big drifts of the frequency on UHF. Stay away

[@nielspDK]

Hi, it look's bad, I look at your video , where some broken traces from the CPU to solder settings , are there not somme missing vias for pullup at nr. 2 and 3 ?

[@mariannevanoostenbrugge3541]

what about the loose yellow wire ,near the lithium, that was the first thing i would fix , communication of the switches worked , because de dial changed the frequency during the first second,

[@TheConstitutionalGuardian]

HolyFuck! Some people should just not own a fucking soldering iron!

[@LuizFernando-ij1pc]

I said that like number 67 was mine here in Brazil! Very good work and knowledge, congratulations TRX Bench.

[@TRXLab]

Thanks Luiz!

[@JosephLorentzen]

Opps, I started my comment about freeze spray and saw someone else has made it.

[@emylrmm]

The owner must have been a real hack to have done such a sloppy job. If you want to know how to solder, read an old Heathkit manual.

[@markkut9419]

Seen equivalent "mods" what destroy radio totally useless There is always persons who think known how to do

[@SupaFUZZZZZZ]

Moral of the story. Do not open the case if you don't know what you are doing. A good tech is worth the price.

[@jerrypeal653]

Given everything you checked I can see why you conclude that processor took a hit .

[@markhod1960]

Great job, that radio was a mess.

[@KR8T]

It looks like the electrlitic cap leaked and damaged the board by the ref osc. A very poor repair.

[@FSR-v9c]

i personaly wont work on something that looks like that when i open it, if someone has done butchered the radio then im out.

[@captlarry-3525]

old, blind, or stupid. I'm getting close enough to all 3 to say that could account for this. when a guy has been doing half -vast repairs on tube or discrete transistor rigs from 40 years ago, his whole life. he is tempted to jump into one of these robot built radios and take a whack at some surface mount stuff with the old reliable 40 watt iron... the smart money will realize that they are licked, when they see that the guys who actually do work on this stuff have microscopes, special micro soldering irons and hot air irons and golly gee whiz.. just send it out !

[@TRXLab]

yes fully agree Larry!

[@TonyLing]

I never understand how some people can be so inept with a soldering iron

[@Gw0wvl]

Don't you just hate it when people armed with a soldering iron , But lacking in any common sense goes inside a radio and they basically ruin it .

[@TRXLab]

Yes so true ;-)

[@kaleembaig319]

Awesome try 🙂, actually this happens when you take your beloved radio to unprofessional repair centers. Say no to modifications. The radio was designed by world's best engineers, you guys don't need to modify anything. Leave it as it is and will always be faithful.

[@ATOMSHAMRADIO]

Someone musta been drinking working on that poor radio what a shame

[@emylrmm]

might have been worthwhile to re-flash the firmware to see if that cleared the problem

[@CodfishCatfish]

I’m sure you covered these but the screw terminals even with power connected went dry joint and I had re-flow these. I had an issue where headphones were once plugged into CW socket in a clients radio and it went into TX as power on and over current. Obviously not what’s going on here but the surface mounts caps are normally 45c working from factory..... yes honestly they are as I worked on camcorders in the 1990s and must have changed 10,000 of the caps for 85c and 105c to give the camcorder a better future. Canon E90 especially. I had this problem on my C2 and trying really hard to remember how I fixed it. See my videos as my C2 is alive and working the birds. Let me check my notes but I’m sure I re-flowed something near the power section. 5 years ago or more....

[@rogersmith2158]

Hi I have a yaesu FT 847 with no audio on transmit on any band or any mode and also intermittent weak receive , if the PTT key is pushed sometimes the receive works again. Any help that you can offer would be greatly appreciated. Thanks in advance.

[@TRXLab]

I'm sorry to many root causes possible that I can't say on remote.

[@danluzurriaga6035]

This video illustrates that the advantages of using processor technology with AMATEUR radio is FAR outweighed by the fact that you cannot repair them 5 years after discontinuation (they fail 6 years after parts discontinuation lol). No reason at all the digitize these radios. When they fail out of warranty they are often just an expensive pile of junk. Yaesu could have also standardized on that CPU and kept it around for future designs; they designed the CPU. They allow their radios to go obsolete. Too bad. Building and repairing digitized radios is not for amateurs but that sort of defeats the purpose of "amateur" radio, right? Not turning the future generations into appliance operators. If the guy has purchased an FT-101, he could still be on the air today. And you commenters, highly trained elitists who sneer at the guy (AMATEUR being an amateur) who tried to fix it...words are not enough...

[@user-uv4xe3cq2y]

Perhaps the owner didn't wear his anti-static wrist band and zapped that chip.

[@Swataia]

Hi! Nice video and explanations how different parts of the radio communicate to each other. And yes, this video should be a warning what can happen to all those who will take the old 100W big soldering iron that they used with great success in the 1960's. I have seen stuff like this. And if you still have the radio around, I would give you a hint to try. I have an FT-847 and I did a MARS mod to it, or tried to do. It was bought from German Ebay back around the 2010, so I think it came with your area software and settings. I followed the info on the internet and it didn't work, if I remember right I was on a same kind of situation where it just rebooted itself like that radio. I returned those "jumpers" to original and it worked again. I think there might be different versions of the processor or memory that will not work with MARS-modification settings or with info of the original settings you find from internet. But if you are really sure what pads were connected at factory this might be not the case. But still an easy one to try. By the way, excellent job with repairing those missing traces! I have a working FT-847 here so if you want some info to compare, you can message me.

[@Swaggerlot]

I think it must have been a plumber that worked on that radio!

[@stevejones8665]

Hahaha That's what I thought too.

[@tumbleweed-life]

A plumber will be able to solder better than that or he would have leaks everywhere,

[@TheMaddogronh]

Did you do a factory CPU reset ?

[@MrPerrey]

Yes, he did but no sucess

[@LuizFernando-ij1pc]

Sorry for writing in Portuguese but it is force of habit because I follow the video channel of Yvo Miniz '' Alpha Telecom '' and always put some comment or questions to him and did not even touch me that I had posted in my local language ok! you're sorry OBS: Just to know, what's your name please!

[@TRXLab]

no worries no problem at all. name is Peter

[@herbertsusmann986]

Is the power supply shutting down? If so, can you force it to stay on?

[@TRXLab]

No power supply is fine and no voltage regulator is collapsing...

[@rickhunt3183]

Imagine someone doing that sloppy work on a customer's radio. After opening the radio and doing an inspection. I wouldn't work on it. I bet the manufacturer or an authorize service center would refuse the work too.

[@TRXLab]

many collegians of mine are refusing to fix a radio if it is older than 5 years...

[@Billblom]

There were connections that looked "smoked" like lightning struck or something.... I would need a microscope to work on the board..but have gone thru the Nasa soldering school.... That sort of damage indicates a bit of ham handed use of a solder gun...

[@Rich-fr5td]

Hi Peter, When the radio shuts down, I hear a relay click, can you trace back from the relay to see what is shutting the relay down. Thanks for all the great videos.

[@TRXLab]

Thanks Rich, I have by passed the relay to see if everything works stable...

[@MrPerrey]

@@TRXLab - And, Peter, by- passing the relay, whats happen then?

[@stargazer7644]

@@MrPerrey Please watch the video. 1:07:31

[@MrPerrey]

@@stargazer7644 - Now I saw it. Peter did o many things - I'm convinced that's the uC, sadly...

[@kennethschultz6465]

I don't know if you know this.. the 847 don't like All MARS Band's 6m and 75m On of the thing's is mis matched antennas .. IT can reset the CPU And 75m is known to roast the driver ... As well as resetting the CPU Just some of the few thing the 847 ain't too fund of ...

[@Weidling81]

Well the line right next to the Batt- terminal looks broken.

[@lscsnv27]

Mr, there is one great thing I would like to know about you, and is where are you from, and if I can get from you some books on electronics, in especially transceiver radios, how and where can I get antenna buster for a radio that i have its a cobra, 18wxst11 40 channels, please thank you

[@thomasjones145]

I don't understand what would posses someone to break an expensive radio like this. Heck, I just got my extra, and all I have is an ht.

[@vicentecamilo5636]

What a shame. The front panel was destroyed.

[@frantech6935]

I'm only at the point where you found the 2.2K resistor. I bought a broken radio for $300 that was dead. I troubleshot the radio only to find the 100ohm resistor was open. I thought that the resistor was too small and had too much current running through it and decided it needed to be larger. I replaced it with a 2.2K resistor and the radio came to life. I then happened to google the problem (after the I fixed it) and found this to be a common problem and Yaesu made an engineering change to replace the resistor with a 2.2K resistor :-) That may be why it was replaced...poorly so unfortunately.

[@cliffcollins4124]

Man you are very clever and extremely interesting. I like watching you work. BUT for crying out loud,, GET ON WITH IT. Talk about long-winded. But I'll keep watching till my battery looses charge and the solenoid holding my eyelids open finally fails

[@TRXLab]

Get playback Speed up to 2.0 that might help....

[@cliffcollins4124]

​@@TRXLab Thankyou, Guess it will disappoint a lot of us to learn Donald Duck is just as clever as we believe you to be.

[@pixeluser8243]

Yaesu Christ, it's a wonder the person who did the messy damages, found the right screwdriver to open the case.

[@TRXLab]

lol yeah hard to believe..

[@MAURICIOFALCAOPY5MZ]

Another FANTASTIC video!! Congratulations Peter from Brazil. 73 from PY5MM- Mauricio

[@LuizFernando-ij1pc]

O like número 67 foi meu aqui no Brasil !Muito bom o trabalho e conhecimento,parabéns TRX Bench .

[@TRXLab]

do not understand what you mean..

[@jackiegreen9636]

I never seen do that before I have same radio since 2001 and still works to this day works great for me so far never have any problem with great video Peter !

[@anthonyrosa5006]

I just got mine back from a shop in Texas. I bought it used as a newly licenced ham from a reputable shop. There was a few months delay before I started using it on HF since I was only on UHF and didn't realize there was an issue. It had terrible receive quality on HF and I didn't realize the volume was very low. They did several mods including the power switch, found the short causing the issue and brought everything into compliance of spec. It works wonderfully now and its much louder..